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Further optimize _.template by controlling how the with-statement is inserted.

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Former-commit-id: a62331e771302f9390d5aca04f878b839fe11b69
This commit is contained in:
John-David Dalton
2012-07-05 11:26:17 -04:00
parent a5fe1eb5fb
commit fe6aa8a6fc
4 changed files with 109 additions and 69 deletions
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11
build.js
View File

@@ -718,19 +718,20 @@
// remove unnecessary code
code = code
.replace(/, *__t, *__j *= *Array.prototype.join|function print[^}]+}/g, '')
.replace(/, *__t,[^;]+|function print[^}]+}/g, '')
.replace(/'(?:\\n|\s)+'/g, "''")
.replace(/__p *\+= *' *';/g, '')
.replace(/(__p *\+= *)' *' *\+/g, '$1')
.replace(/\+\s*' *';/g, ';')
.replace(/(\{) *;|; *(\})/g, '$1$2')
.replace(/\(\(__t *= *\( *([^)]+) *\)\) *== *null *\? *'' *: *__t\)/g, '$1');
.replace(/\(\(__w?t *= *\( *([^)]+) *\)\) *== *null *\? *'' *: *__w?t\)/g, '$1');
// remove the with-statement
code = code.replace(/ *with *\([^)]+\) *{/, '\n').replace(/\s*}(\s*)return /, '$1return ');
code = code.replace(/ *with *\([^)]+\) *{/, '\n').replace(/}}\s*;?\s*}/, '}}\n');
// minor cleanup
code = code.replace(/var __p;\s*__p/, 'var __p');
code = code
.replace(/obj *\|\| *\(obj *= *\{}\);/, '')
.replace(/var __p;\s*__p/, 'var __p');
// remove comments, including sourceURLs
code = code.replace(/\s*\/\/.*(?:\n|$)/g, '');

13
build/pre-compile.js
View File

@@ -224,12 +224,17 @@
});
// remove whitespace from `_.template` related regexpes
source = source.replace(/(?:reEmptyString\w+|reInsertVariable) *=.+/g, function(match) {
return match.replace(/ /g, '');
source = source.replace(/(?:reDelimiterCode\w+|reEmptyString\w+|reInsertVariable) *=.+/g, function(match) {
return match.replace(/ |\\n/g, '');
});
// remove newline from double-quoted string in `_.template`
source = source.replace('"\';\\n"', '"\';"');
// remove newline from double-quoted strings in `_.template`
source = source
.replace('"\';\\n__with ("', '"\';__with("')
.replace('"\\n}__\\n__p += \'"', '"}____p+=\'"')
.replace('"__p = \'"', '"__p=\'"')
.replace('"\';\\n"', '"\';"')
.replace("') {\\n'", "'){'")
// remove `useSourceURL` variable
source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *try *\{(?:\s*\/\/.*\n)* *var useSourceURL[\s\S]+?catch[^}]+}\n/, '');

150
lodash.js
View File

@@ -9,11 +9,29 @@
'use strict';
/**
* Used to match potentially incorrect data object references, like `obj.obj`,
* in compiled templates. The variables are assigned in `_.template`.
* Used to cache the last `_.templateSettings.evaluate` delimiter to avoid
* unnecessarily assigning `reEvaluateDelimiter` a new generated regexp.
* Assigned in `_.template`.
*/
var lastVariable,
reDoubleVariable;
var lastEvaluateDelimiter;
/**
* Used to cache the last template `options.variable` to avoid unnecessarily
* assigning `reDoubleVariable` a new generated regexp. Assigned in `_.template`.
*/
var lastVariable;
/**
* Used to match potentially incorrect data object references, like `obj.obj`,
* in compiled templates. Assigned in `_.template`.
*/
var reDoubleVariable;
/**
* Used to match "evaluate" delimiters, including internal delimiters,
* in template text. Assigned in `_.template`.
*/
var reEvaluateDelimiter;
/** Detect free variable `exports` */
var freeExports = typeof exports == 'object' && exports &&
@@ -36,13 +54,21 @@
/** Used to restore the original `_` reference in `noConflict` */
var oldDash = window._;
/** Used to match empty strings in compiled templates */
/** Used to detect delimiter values that should be processed by `tokenizeEvaluate` */
var reComplexDelimiter = /[-)}={(+]|\[\D/;
/** Used to match code generated in place of template delimiters */
var reDelimiterCodeLeading = /^';\n/,
reDelimiterCodeMiddle = /^' \+\n/,
reDelimiterCodeTrailing = /(?:__p \+= '|\+\n')$/;
/** Used to match empty string literals in compiled template source */
var reEmptyStringLeading = /\b__p \+= '';/g,
reEmptyStringMiddle = /\b(__p \+?=) '' \+/g,
reEmptyStringTrailing = /(__e\(.*?\)|\b__t\)) \+\n'';/g;
reEmptyStringTrailing = /(__w?e\(.*?\)|\b__w?t\)) \+\n'';/g;
/** Used to insert the data object variable into compiled templates */
var reInsertVariable = /(?:__e|__t = )\(\s*(?![\s"']|this\.)/g;
/** Used to insert the data object variable into compiled template source */
var reInsertVariable = /(?:__e|__t = )\(\s*(?![\d\s"']|this\.)/g;
/** Used to detect if a method is native */
var reNative = RegExp('^' +
@@ -54,7 +80,7 @@
/** Used to match tokens in template text */
var reToken = /__token__(\d+)/g;
/** Used to match unescaped characters in HTML */
/** Used to match unescaped characters in strings for inclusion in HTML */
var reUnescapedHtml = /[&<"']/g;
/** Used to match unescaped characters in compiled string literals */
@@ -88,7 +114,7 @@
nativeIsFinite = window.isFinite,
nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys;
/** Object#toString result shortcuts */
/** `Object#toString` result shortcuts */
var arrayClass = '[object Array]',
boolClass = '[object Boolean]',
dateClass = '[object Date]',
@@ -480,7 +506,7 @@
}
/**
* Used by `sortBy()` to compare transformed values of `collection`, sorting
* Used by `sortBy` to compare transformed values of `collection`, sorting
* them in ascending order.
*
* @private
@@ -502,7 +528,7 @@
}
/**
* Used by `template()` to replace tokens with their corresponding code snippets.
* Used by `template` to replace tokens with their corresponding code snippets.
*
* @private
* @param {String} match The matched token.
@@ -514,7 +540,7 @@
}
/**
* Used by `template()` to escape characters for inclusion in compiled
* Used by `template` to escape characters for inclusion in compiled
* string literals.
*
* @private
@@ -526,7 +552,7 @@
}
/**
* Used by `escape()` to escape characters for inclusion in HTML.
* Used by `escape` to escape characters for inclusion in HTML.
*
* @private
* @param {String} match The matched character to escape.
@@ -576,7 +602,7 @@
});
/**
* Used by `template()` to replace "escape" template delimiters with tokens.
* Used by `template` to replace "escape" template delimiters with tokens.
*
* @private
* @param {String} match The matched template delimiter.
@@ -584,27 +610,41 @@
* @returns {String} Returns a token.
*/
function tokenizeEscape(match, value) {
if (reComplexDelimiter.test(value)) {
return '<e%-' + value + '%>';
}
var index = tokenized.length;
tokenized[index] = "' +\n__e(" + value + ") +\n'";
return token + index;
}
/**
* Used by `template()` to replace "evaluate" template delimiters with tokens.
* Used by `template` to replace "evaluate" template delimiters, or complex
* "escape" and "interpolate" delimiters, with tokens.
*
* @private
* @param {String} match The matched template delimiter.
* @param {String} value The delimiter value.
* @param {String} escapeValue The "escape" delimiter value.
* @param {String} interpolateValue The "interpolate" delimiter value.
* @returns {String} Returns a token.
*/
function tokenizeEvaluate(match, value) {
function tokenizeEvaluate(match, value, escapeValue, interpolateValue) {
var index = tokenized.length;
tokenized[index] = "';\n" + value + ";\n__p += '";
if (value) {
tokenized[index] = "';\n" + value + ";\n__p += '"
}
else if (escapeValue) {
tokenized[index] = "' +\n__we(" + escapeValue + ") +\n'";
}
else if (interpolateValue) {
tokenized[index] = "' +\n((__wt = (" + interpolateValue + ")) == null ? '' : __wt) +\n'";
}
return token + index;
}
/**
* Used by `template()` to replace "interpolate" template delimiters with tokens.
* Used by `template` to replace "interpolate" template delimiters with tokens.
*
* @private
* @param {String} match The matched template delimiter.
@@ -612,6 +652,9 @@
* @returns {String} Returns a token.
*/
function tokenizeInterpolate(match, value) {
if (reComplexDelimiter.test(value)) {
return '<e%=' + value + '%>';
}
var index = tokenized.length;
tokenized[index] = "' +\n((__t = (" + value + ")) == null ? '' : __t) +\n'";
return token + index;
@@ -3203,9 +3246,7 @@
options || (options = {});
var endIndex,
isEscaping,
isEvaluating,
isInterpolating,
startIndex,
result,
useWith,
@@ -3225,18 +3266,25 @@
if (interpolateDelimiter == null) {
interpolateDelimiter = defaults.interpolate;
}
// tokenize delimiters to avoid escaping them
if (escapeDelimiter) {
isEscaping = text != (text = text.replace(escapeDelimiter, tokenizeEscape));
text = text.replace(escapeDelimiter, tokenizeEscape);
}
if (interpolateDelimiter) {
isInterpolating = text != (text = text.replace(interpolateDelimiter, tokenizeInterpolate));
text = text.replace(interpolateDelimiter, tokenizeInterpolate);
}
if (evaluateDelimiter) {
startIndex = tokenized.length;
isEvaluating = text != (text = text.replace(evaluateDelimiter, tokenizeEvaluate));
endIndex = tokenized.length - 1;
if (evaluateDelimiter != lastEvaluateDelimiter) {
lastEvaluateDelimiter = evaluateDelimiter;
reEvaluateDelimiter = RegExp(
(evaluateDelimiter ? evaluateDelimiter.source : '($^)') +
'|<e%-([\\s\\S]+?)%>|<e%=([\\s\\S]+?)%>'
, 'g');
}
startIndex = tokenized.length;
text = text.replace(reEvaluateDelimiter, tokenizeEvaluate);
endIndex = tokenized.length - 1;
isEvaluating = startIndex <= endIndex;
// if `options.variable` is not specified and the template contains "evaluate"
// delimiters, inject a with-statement around all "evaluate" delimiters to
@@ -3246,22 +3294,14 @@
useWith = isEvaluating;
if (useWith) {
tokenized[startIndex] =
tokenized[startIndex].slice(0, 3) +
'__with (' + variable + ') {\n' +
tokenized[startIndex].slice(3);
tokenized[startIndex] = "';\n__with (" + variable + ') {\n' + tokenized[startIndex]
.replace(reDelimiterCodeLeading, '')
.replace(reDelimiterCodeMiddle, '__p += ');
tokenized[endIndex] =
tokenized[endIndex].slice(0, -8) +
'}__\n' +
tokenized[endIndex].slice(-8);
tokenized[endIndex] = tokenized[endIndex]
.replace(reDelimiterCodeTrailing, '') + "\n}__\n__p += '";
}
}
// memoize `reDoubleVariable`
if (variable != lastVariable) {
lastVariable = variable;
reDoubleVariable = RegExp('([(\\s])' + variable + '\\.' + variable + '\\b', 'g');
}
var strInsertVariable = '$&' + variable + '.',
strDoubleVariable = '$1__d';
@@ -3278,9 +3318,13 @@
// find the start and end indexes of the with-statement
if (useWith) {
startIndex = text.indexOf('__with');
endIndex = text.indexOf('}__', startIndex + 12);
endIndex = text.indexOf('}__', startIndex + 10);
}
// memoize `reDoubleVariable`
if (variable != lastVariable) {
lastVariable = variable;
reDoubleVariable = RegExp('([(\\s])' + variable + '\\.' + variable + '\\b', 'g');
}
// inject data object references outside of the with-statement
text = (useWith ? text.slice(0, startIndex) : text)
.replace(reInsertVariable, strInsertVariable)
@@ -3293,27 +3337,17 @@
: ''
);
// cleanup compiled code by stripping empty strings
// cleanup code by stripping empty strings
text = (isEvaluating ? text.replace(reEmptyStringLeading, '') : text)
.replace(reEmptyStringMiddle, '$1')
.replace(reEmptyStringTrailing, '$1;');
// wrap function body
// frame code as the function body
text = 'function(' + variable + ') {\n' +
(useWith
? variable + ' || (' + variable + ' = {});\n'
: ''
) +
'var __p' +
(isInterpolating
? ', __t'
: ''
) +
variable + ' || (' + variable + ' = {});\n' +
'var __p, __t, __wt' +
', __d = ' + variable + '.' + variable + ' || ' + variable +
(isEscaping
? ', __e = _.escape'
: ''
) +
', __e = _.escape, __we = __e' +
(isEvaluating
? ', __j = Array.prototype.join;\n' +
'function print() { __p += __j.call(arguments, \'\') }\n'
@@ -3333,7 +3367,7 @@
if (data) {
return result(data);
}
// provide the compiled function's source via its `toString()` method, in
// provide the compiled function's source via its `toString` method, in
// supported environments, or the `source` property as a convenience for
// build time precompilation
result.source = text;

4
perf/perf.js
View File

@@ -699,7 +699,7 @@
/*--------------------------------------------------------------------------*/
suites.push(
Benchmark.Suite('`_.template` without "evaluate" delimiters')
Benchmark.Suite('`_.template` without "evaluate" delimiters (slow path)')
.add('Lo-Dash', function() {
lodash.template(tpl, tplData);
})
@@ -709,7 +709,7 @@
);
suites.push(
Benchmark.Suite('`_.template` with "evaluate" delimiters')
Benchmark.Suite('`_.template` with "evaluate" delimiters (slow path)')
.add('Lo-Dash', function() {
lodash.template(tplWithEvaluate, tplData);
})